JP2009244546A - Color filter substrate and liquid crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To compensate for phase difference variation of transmitted light of each colored pixel caused by both optical anisotropy by a material composing a colored pixel and wavelength dispersibility in refractive index of a liquid crystal material by adjusting only a phase difference control layer of a color filter substrate having a colored pixel layer on a transparent substrate and the phase difference control layer containing a liquid crystalline compound over the colored pixel layer. <P>SOLUTION: The color filter substrate is characterized in that the phase difference control layer irradiates an ultraviolet-curing type liquid crystalline compound with ultraviolet rays through a photomask having a full-light-shield area and a full-transmission area, and a half-light-shield area of 0 to 40% in light transmissivity for a wavelength of 300 to 340 nm, 5 to 80% for 340 to 370 nm, and 20 to 100% for 370 to 500 nm to contain a liquid crystalline compound which is different in degree of orientation by colors of the colored pixel layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a color filter substrate having a liquid crystal phase difference control layer for improving viewing angle characteristics of a liquid crystal display.

  Various types of displays such as liquid crystal displays, plasma displays, and organic EL displays have been put into practical use. In these displays, a retardation control layer is often used in combination with a linear polarizing plate. For example, any combination of a linear polarizing plate and a quarter-wave retardation plate, a half-wave retardation plate, a quarter-wave retardation plate and a circular polarizing plate, and a circular polarizing plate combining a linear polarizing plate By providing it on the viewing side of the display, external light reflection is prevented and display contrast is improved. In addition, in a reflective liquid crystal display or a transflective liquid crystal display, a circularly polarizing plate or an elliptically polarizing plate is used to enhance the light shielding effect of liquid crystal molecules.

  Furthermore, a phase difference plate is used to improve color compensation and viewing angle characteristics of a super twisted nematic mode (STN) liquid crystal display. Particularly in recent years, in a vertical alignment mode (MVA) liquid crystal display capable of high-contrast display, a retardation film (negative C plate) having an optical axis perpendicular to the substrate and having negative birefringence anisotropy, and an optical axis Is a phase difference film (positive A plate) which is horizontal to the substrate and has positive birefringence anisotropy. (For example, refer to Patent Document 1).

  The usual method for controlling the phase difference in the above-mentioned document 1 is that a polymer film such as a polycarbonate film is usually stretched or a liquid crystal material having birefringence anisotropy is applied to the entire surface of a triacetyl cellulose film and then solidified. A retardation control film is used.

  However, in the retardation control film manufactured by the above method, the retardation value is kept uniform in the plane, but what is actually required is the setting of the optimum retardation value for each colored pixel. However, the optimum phase difference is not necessarily compensated.

  For example, since the refractive index of the liquid crystal itself has a wavelength dependence with respect to the transmitted light, the required phase difference value differs depending on each colored pixel constituting the color filter. For this, Patent Document 2 discloses an attempt to perform phase difference compensation more optimally by controlling the phase difference value in accordance with the wavelength range of transmitted light.

  However, in practice, when the above measures are taken, there is a problem that when black display is observed from an oblique direction, red or blue leakage light is observed, and phase difference compensation is not completely performed.

  This is because the colored pigments used in the red, green and blue colored pixels have optical anisotropy, and the degree of anisotropy varies depending on the type of pigment. Usually, since optical design is performed centering on green, if the phase difference values of the red / blue and green color filter layers are significantly different from each other in positive and negative, red and blue leakage light occurs as described above.

In Patent Document 3, the thickness of each color pixel constituting the color filter is formed so as to correspond to each color, and a phase difference control layer made of a liquid crystalline polymer is formed on the color filter layer and the phase difference control. A color filter is disclosed that includes a phase difference control layer that is laminated so that the total thickness of the layers is constant and has a phase difference amount corresponding to display pixels of three colors. In this method, the retardation per unit thickness of the retardation control layer is constant, and the difference in retardation is expressed in proportion to the thickness of the retardation control layer. Is important to.

However, in the above configuration, it is necessary to form the retardation control layer on the color filter layer having a thickness difference so that the thicknesses of the color filter layer and the retardation control layer are constant, and this method itself is extremely difficult. In addition, since it is necessary to strictly control the thickness of the color filter layer, there is a problem that the degree of freedom in designing the color filter is limited or the manufacturing difficulty of the color filter is increased.
JP-A-10-153802 (pages 12-13, FIG. 54) JP-A-2005-148118 JP 2005-24919 A

  Therefore, an object of the present invention is to change the phase difference of transmitted light for each colored pixel caused by both the optical anisotropy of the material composing the colored pixel and the wavelength dispersion of the refractive index of the liquid crystal material from the liquid crystal material. The phase difference of the phase difference control layer is not compensated not only by the phase difference control layer, but also by the precise control of the contribution from the colored pixel layer by paying attention to the film thicknesses of both. The present invention provides means for realizing phase difference compensation sufficiently and easily by adjusting the amount for each portion corresponding to each colored pixel without depending on the thickness. That is, a color that compensates for each color pixel by changing the phase difference caused by both the optical anisotropy due to the material composing the colored pixel and the wavelength dispersion of the refractive index of the liquid crystal material only by adjusting the phase difference control layer. A filter substrate is provided.

  The invention of claim 1 of the present invention is a color filter substrate comprising a colored pixel layer on a transparent substrate and a retardation control layer containing a liquid crystal compound below or above the colored pixel layer, wherein the retardation control layer comprises: A photomask having a total light-shielding region and a total light-transmitting region, and a semi-light-shielding region having a light transmittance of 0 to 40% at wavelengths of 300 to 340 nm, 5 to 80% at 340 to 370 nm, and 20 to 100% at 370 to 500 nm UV light is applied to the UV curable liquid crystal compound applied to the lower part or the upper part of the colored pixel layer, and the liquid crystal compound having a different degree of orientation for each color of the colored pixel layer is included. The color filter substrate characterized by the above.

  By using the mask having such a configuration, a change in retardation per unit thickness can be induced by changing the alignment state of the liquid crystalline material composing the retardation control layer.

  According to a second aspect of the present invention, the ultraviolet curable liquid crystal compound comprises at least a thermotropic liquid crystal compound having a polymerizable and / or crosslinkable functional group, a light and / or thermal polymerization initiator. The color filter substrate according to claim 1, further comprising:

  By adopting such a material composition, it is possible to easily realize fixing of different retardation values for each location per unit thickness.

  A third aspect of the present invention is a liquid crystal display device using the color filter substrate according to the first or second aspect.

As described above, according to the present invention, the difference in retardation due to the driving liquid crystal and the coloring material is not compensated by adjusting the thicknesses of both the coloring layer and the retardation control layer, but the retardation control. Since the retardation value per unit thickness of the layer is adjusted for each colored pixel portion, it is easy to realize an optimum amount of retardation for each colored pixel, and the load of the manufacturing process accompanying the thickness control is greatly reduced. It becomes possible. As a result, the thickness of the colored pixels constituting the color filter and the degree of freedom in selecting the material are increased. Therefore, by using the color filter thus obtained, a liquid crystal display with excellent display image quality can be provided.

  Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings.

  First, the color filter substrate of the present invention will be described in the order of constituent materials. In the following, a color filter substrate in which a colored pixel layer is formed on a transparent substrate and a liquid crystal retardation layer formed by laminating the liquid crystal compound is described as an example.

  FIG. 1 is a sectional view showing the configuration of a color filter substrate having a liquid crystal retardation layer according to the present invention. This is because a black matrix 3 made of a light-shielding material is formed at a position corresponding to a non-pixel portion on the transparent substrate 2, and light transmission is possible at each position corresponding to each opening of the black matrix 3. The colored pixel layer 4 in which the respective color patterns of the red pattern 4R, the green pattern 4G, and the blue pattern 4B are arranged is formed, and a liquid crystal retardation layer containing a liquid crystal compound is formed on the colored pixel layer 4 Each has a structure in which 5R, 5G, and 5B are stacked. In this color filter substrate, the liquid crystal compound is fixed in a state where there is a difference in the degree of orientation of the liquid crystal compound, and by making the degree of orientation different, a difference is caused in the birefringence of the liquid crystal layer, As a result, the phase difference amounts are also different values. For example, if the liquid crystal molecules are almost perfectly aligned, the birefringence is strong, that is, the retardation value is large. Conversely, if the degree of orientation is low, the birefringence is weak, that is, the retardation value. As it becomes small. Further, as a limit of a state where the degree of alignment of the liquid crystal is low, the liquid crystal compound may be fixed in an unaligned state. In this case, the liquid crystal is approximately isotropic, and the liquid crystal retardation region is substantially positioned. Since no phase difference occurs, it acts as a simple transparent layer.

  In the color filter substrate of the present invention, the liquid crystal retardation layer has different degrees of orientation by irradiating the liquid crystal compound with ultraviolet to visible light through a photomask having different transmittances in partial portions. The liquid crystal retardation layer is formed in a lump over a plurality of regions. That is, the degree of orientation is high in the liquid crystal compound layer region corresponding to the total transmission region where the irradiation light is almost transmitted, and conversely, the liquid crystal compound layer region corresponding to the total light shielding region where the irradiation light is blocked is optical. It is almost isotropic. On the other hand, in the liquid crystal compound layer region corresponding to the semi-transmission region that is in the middle, ultraviolet rays on the short wavelength side are selectively cut, so the degree of orientation is the same as that of the liquid crystal compound layer region corresponding to the total transmission region. An intermediate value with respect to the liquid crystal compound layer region corresponding to the entire light shielding region can be obtained. The phase difference per unit thickness varies with the degree of orientation.

  The most significant feature of the present invention is that a photomask having a semi-light-shielding region having a light transmittance of 0 to 40% at a wavelength of 300 to 340 nm, 5 to 80% at 340 to 370 nm, and 20 to 100% at 370 to 500 nm is used. It is to irradiate a liquid crystal compound. In general, a Cr thin film is used as a light-shielding portion of a photomask, and the same applies to the present invention. By using a compound thin film containing, or a compound thin film containing Ti, Mo or the like, it is possible to form semi-transmissive regions having different transmittances over a wide wavelength range.

  In addition, the liquid crystal retardation layer of the present invention is coated with a solution containing at least a thermotropic property and having a functional group capable of polymerization and / or cross-linking, a light and / or a thermal polymerization initiator, and ultraviolet rays. Can be formed by using both irradiation and heating.

  Examples of the liquid crystal compound include alkylcyanobiphenyl, alkoxybiphenyl, alkylterphenyl, phenylcyclohexane, biphenylcyclohexane, phenylbicyclohexane, pyrimidine, cyclohexanecarboxylic acid ester, halogenated cyanophenol ester, alkylbenzoic acid ester, alkylcyanotolane. Dialkoxytolane, alkylalkoxytolane, alkylcyclohexyltolane, alkylbicyclohexane, cyclohexylphenylethylene, alkylcyclohexylcyclohexene, alkylbenzaldehyde azine, alkenylbenzaldehyde azine, phenylnaphthalene, phenyltetrahydronaphthalene, phenyldecahydronaphthalene and their derivatives, and Said compound And the like acrylates and epoxy-modified product.

  The photopolymerization initiator is a compound that can generate active species such as radical species by irradiation with ultraviolet rays or the like. Specifically, a triazine photopolymerization initiator, a carbazole photopolymerization initiator, an imidazole photopolymerization initiator. Borate photopolymerization initiator, acetophenone photopolymerization initiator, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, and the like. A thermal polymerization initiator is a compound that can generate active species by heat, does not exhibit activity under normal conditions of normal temperature and pressure, and is a so-called latent thermal polymerization initiator that generates active species by heat as an external stimulus. Dialkylarylsulfoniums, cycloalkylallylsulfoniums, alkyldiarylsulfonium salts, dialkylarylsulfoniums, triarylsulfoniums, benzylpyridiniums, benzylammoniums, tetrafluoroborate salts of benzyltriarylphosphoniums, Hexafluorophosphate salts, hexafluoroarsenate salts, tetrafluoroantimonate salts and the like can be mentioned.

  The positive and negative retardation values that can be expressed are determined by the alignment state of the liquid crystal, but this is not particularly limited. For example, positive A obtained by homogeneous alignment in which the rod-like liquid crystal is aligned in parallel with the surface in the plane. Plate, positive C plate obtained by homeotropic alignment which is aligned so as to be perpendicular to the in-plane, negative C plate obtained by cholesteric orientation which is parallel to the surface and wound in a plane, and is disk-shaped In the case of liquid crystal, a negative A plate obtained by homeotropic alignment aligned so as to be perpendicular to the surface, a positive C plate obtained by homogeneous alignment aligned parallel to the surface within the surface, and the like. However, the present invention is not limited thereto, and the biaxiality (composite of positive A plate / negative C plate) in which rod-like molecules are in-plane parallel to the surface and spirally wound to deflect the azimuth angle. Etc. also present invention is applicable.

  Next, a specific method for forming the liquid crystal retardation layer on the color filter substrate will be described with reference to FIG.

  First, the color filter substrate is provided with the black matrix 3 for improving the contrast on the transparent substrate 2 (FIG. 2A), and then the colored pixel layer 4R of red (R), green (G), and blue (B). 4G and 4B are formed (FIG. 2B), and when this is used as a cell for a liquid crystal display, a transparent flat layer, a transparent conductive layer, and an alignment film layer are sequentially laminated, and then a thin film transistor is formed. The liquid crystal is encapsulated so as to face the formed counter substrate.

  The colored pixel layer 4 is provided in the opening of the black matrix 3, and a pixel pattern composed of three primary colors of a normal red pixel pattern 4R, a green pixel pattern 4G, and a blue pixel pattern 4B is arranged at a desired position. . Examples of the general production method include a pigment dispersion method, a dye method, an electrodeposition method, a printing method, a transfer method, and an ink jet method. In the present invention, the colored resin composition is patterned by any of these methods. May be.

  A pigment, dye, etc. can be used for the coloring agent of the said colored resin composition. In the present invention, it is preferable to use a pigment having excellent weather resistance. Specifically, Pigment Red 9, 19, 38, 43, 97, 122, 123, 144, 149, 166, 168, 177, 179, 180, 192, 215, 216, 208, 216, 217, 220, 223, 224, 226, 227, 228, 240, 254, Pigment Blue 15, 15: 6, 16, 22, 29, 60, 64, Pigment Green 7, 36, Pigment Yellow 20, 24, 86, 81, 83, 93, 108 109, 110, 117, 125, 137, 138, 139, 147, 148, 150, 153, 154, 166, 168, 185, Pigment Orange 36, Pigment Violet 23, and the like. In order to obtain a more desirable hue, two or more kinds of materials can be mixed and used.

  The thermosetting resin of the colored resin composition can be appropriately selected from casein, gelatin, polyvinyl alcohol, carboxymethyl acetal, polyimide resin, acrylic resin, epoxy resin, melamine resin, and the like. In particular, an acrylic resin is preferably used when manufacturing a color filter that requires heat resistance and light resistance.

  Specific examples of the solvent for the colored resin composition include diethylene glycol-n-butyl ether, tetraethylene glycol dimethyl ether, pentaethylene glycol dimethyl ether, tripropylene glycol methyl ether, dipropylene glycol-n-propyl ether, dipropylene glycol-n. -Butyl ether, tripropylene glycol-n-butyl ether, propylene glycol phenyl ether and the like. In addition, in order to further increase the boiling point of the solvent, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-methoxyethyl acetate, 2 -Ethoxyethyl ether, 2- (2-ethoxyethoxy) ethanol, 2- (2-butoxyethoxy) ethanol, 2- (2-ethoxyethoxy) ethyl acetate, 2- (2-butoxyethoxy) ethyl acetate, 2-phenoxyethanol Diethylene glycol dimethyl ether or the like can be used. Moreover, what mixed and adjusted the 2 or more types of solvent as needed can be used.

  The dispersant for the colored resin composition is used to improve the dispersion of the pigment into the resin. As the dispersant, an ionic or nonionic surfactant can be used. Specific examples include sodium alkylbenzene sulfonate, poly fatty acid salts, fatty acid salt alkyl phosphates, tetraalkyl ammonium salts, polyoxyethylene alkyl ethers, and other organic pigment derivatives and polyesters. One type of dispersant may be used alone, or two or more types of dispersants may be mixed and used.

  For the transparent substrate 2, a transparent substrate material such as a glass substrate, a quartz substrate, or a plastic substrate can be used. Among them, the glass substrate is excellent in transparency, strength, heat resistance, and weather resistance.

  The black matrix 3 is formed, for example, by forming a thin film of metal or metal oxide on a substrate by a method such as sputtering, and patterning it by a method such as etching, or by adding a pigment or A method of forming a photosensitive resin composition layer on a substrate by mixing a colorant such as a dye and forming it by a photolithography method, and further dissolving a black pigment or a thermosetting resin in a solvent and forming it by a printing method. It can be manufactured by a method.

  Next, a method for producing the liquid crystal retardation layer according to the present invention from the liquid crystal compound will be described.

  A solution containing the above-mentioned liquid crystal compound is applied onto the colored pixels 4 formed on the color filter substrate. At this time, it is necessary to form a layer expressing the liquid crystal alignment regulating force on the colored pixel 4. For example, the liquid crystal alignment regulation force can be obtained by rubbing the polyimide layer. Examples of the application method of the liquid crystal compound solution include known methods such as a spin coating method, a slit coating method, a printing method such as a relief plate, a screen, and a planographic plate, and an ink jet method.

Subsequently, after drying the solvent, pattern exposure is performed by irradiating ultraviolet rays through the photomask 6 having the total transmission region 6a, the semi-light-shielding region 6b, and the total light-shielding region 6c (FIG. 2C). It controls the degree of alignment of the liquid crystal retardation layer (FIG. 2 (d)). The ultraviolet ray irradiated at this time is set to an irradiation amount sufficient to align the liquid crystal compound in the liquid crystal layer region corresponding to the total transmission region almost completely. Thus, in the liquid crystal retardation layer 5R corresponding to the entire transmission region on the colored pixel layer 4R, the liquid crystal compound is cured while maintaining the alignment state, and the liquid crystal retardation corresponding to the semi-transmission region on the colored pixel 4G is obtained. The layer 5G is partially cured leaving an uncured component, and the liquid crystal retardation layer 5B corresponding to all the light shielding regions on the colored pixels 4B and the black matrix 3 remains in an uncured liquid crystal state. The irradiation amount of ultraviolet rays addition amount of the photopolymerization initiator, or varies depending on the type and illuminance of the radiation is preferably in the range of, for example, ^{1mJ / cm 2 ~10000mJ / cm 2} . Moreover, it is preferable that the atmosphere irradiated with ultraviolet rays is an inert gas atmosphere such as a nitrogen atmosphere. Thereby, it can harden | cure without being influenced by oxygen and the optical characteristic of the liquid crystal phase difference layer 5 can be stabilized. Moreover, it is possible to adjust the curing degree of the liquid crystal retardation layer 5G corresponding to the semi-transmissive region by appropriately setting the type and addition amount of the photopolymerization initiator in the liquid crystal compound.

  By exposing through a mask having different transmittances in this way, the color filter substrate on which the liquid crystal compound exhibiting a different cured state is placed in each region is then brought to the isotropic phase transition temperature of the liquid crystal compound or higher. Heat. Then, in the liquid crystal retardation layer 5R corresponding to the entire transmission region, the liquid crystal compound is already cured, so that the liquid crystal component is fixed and kept in a highly aligned state, and in the liquid crystal retardation layer 5G corresponding to the semi-light-shielding region, The alignment of the liquid crystal component corresponding to the uncured portion is disturbed, resulting in a low alignment state. On the other hand, in the liquid crystal retardation layer 5B corresponding to the entire light shielding region, the liquid crystal component transitions to the isotropic phase and becomes substantially non-oriented.

  Finally, when the entire surface of the substrate is exposed while maintaining the temperature at which the liquid crystal compound is maintained at or above the isotropic phase, the regions in the high alignment state, the medium to low alignment state, and the non-alignment state are polymerized and / or Alternatively, it is cross-linked and immobilized. As a result, liquid crystal retardation layers having different degrees of orientation in each region can be formed. In addition, when performing this whole surface exposure, the said liquid crystal compound requires sufficient irradiation amount which can fully superpose | polymerize and / or bridge | crosslink.

  Finally, the color filter substrate can be held at a higher temperature and re-cured to stabilize the optical characteristics of the liquid crystal retardation layer 5 and to make the film stronger. The temperature at this time is 100 ° C. to 250 ° C. If there is a concern about unnecessary reactions at high temperatures, a lower temperature is desirable.

  Thereby, finally, a color filter in which a liquid crystal retardation layer having liquid crystal retardation layers 5R, 5G, and 5B corresponding to the respective colored pixel regions is formed (FIG. 3D).

As described above, according to the present embodiment, it is possible to control a plurality of phase difference values within a considerable range, corresponding to a display area of a plurality of colored pixels, and an easy and stable production of a color filter substrate can be achieved. . Further, since the phase difference value is adjusted according to the wavelength range of the light passing through the colored pixel region, there is no variation in the degree of polarization of the light passing through each colored pixel region. Furthermore, since viewing angle compensation from an oblique direction is possible, color shift when viewed from an oblique direction can be reduced, and neutral black can be reproduced, and very excellent display characteristics can be obtained.

  Hereinafter, although an example is described, the present invention is not limited to the following example. In addition, since the material used in this embodiment is extremely sensitive to light and heat, it is necessary to prevent exposure to unnecessary light such as natural light, and it goes without saying that all operations are performed under a yellow or red light. Yes.

<Adjustment of liquid crystal composition>
A liquid crystal composition (A) was prepared by stirring a mixture comprising the following composition so as to be uniform.
Polymerizable liquid crystal Palocolor LC 242 (manufactured by BASF Japan) 100 parts by weight chiral agent Paliocolor LC 756 (manufactured by BASF Japan) 9 parts by weight photopolymerization initiator Irgacure 907 (manufactured by Ciba Specialty Chemicals) 4.5 parts by weight Irgacure OXE01 ( 0.5 parts by weight of solvent 1-methoxy-2-propyl acetate 420 parts by weight A mixture of the following compositions was stirred uniformly to prepare a liquid crystal composition (B).

Polymerizable liquid crystal UCL 018 (Dainippon Ink Chemical Co., Ltd.) 100 parts by weight Photopolymerization initiator Irgacure 907 (Ciba Specialty Chemicals) 4.3 parts by weight Irgacure OXE01 (Ciba Specialty Chemicals) 0.2 parts by weight Solvent 420 parts by weight of 1-methoxy-2-propyl acetate

<Preparation of liquid crystal retardation layer>
The liquid crystal compositions (A) and (B) were applied on a glass substrate by spin coating. The mixture was heated at 90 ° C. for 3 minutes, and then the total light shielding region, the total transmission region, and the light transmittance at a wavelength of 300 to 500 nm were shown in FIGS. Exposure was performed at a dose of 200 mJ / cm ² through photomasks A to D having light shielding regions. In addition, in the exposure process, it implemented in nitrogen atmosphere so that superposition | polymerization inhibition by the oxygen in air | atmosphere might not arise.

  Furthermore, in order to stabilize the liquid crystal retardation layer, a liquid crystal retardation layer (A) and (B) was formed through a heating process at 200 ° C. for 30 minutes. The film thicknesses were 1.0 μm and 0.5 μm, respectively.

  Table 1 shows the measurement results of the thickness and retardation value in the thickness direction of the retardation layer formed of the liquid crystal compositions (A) and (B) formed according to the above-described production examples. In the measurement of the phase difference, a phase difference measuring device (manufactured by Oji Scientific Instruments, KOBRA-WR) was used.

<Production of color filter>
A black matrix is formed on a glass substrate, and then a red, green and blue coloring composition is formed in the gaps of the black matrix by photolithography, and the colored pixels (R), colored pixels (G) and colored pixels (B ) Were formed.

  Table 2 shows the measurement result of the retardation value in the thickness direction of the colored pixel layer of the color filter.

<Production of phase-controlled color filter>
On the color filter produced above, a thermosetting resin composition mainly composed of an epoxy compound was applied, dried, and then subjected to a heat process at 230 ° C. for 1 hour to form a transparent flat layer having a thickness of 1.2 μm.

  Then, it apply | coated on the glass substrate by spin coat. Heating at 90 ° C. for 3 minutes, and then using an ultraviolet irradiation device using an ultrahigh pressure mercury lamp as a light source, through any of photomasks A to D having a full transmission region, a total light shielding region, and a semi-light shielding region, Positioning was performed so that each colored pixel region and each region of the photomask correspond to each other, and exposure was performed at an irradiation amount of 200 mJ / cm 2. The exposure process was performed under a nitrogen atmosphere so that polymerization inhibition by oxygen in the atmosphere did not occur.

  Furthermore, in order to stabilize the liquid crystal retardation layer, a liquid crystal retardation layer (A) and (B) was formed through a heating process at 200 ° C. for 30 minutes. The film thicknesses were 1.0 μm and 0.5 μm, respectively.

  Tables 3 and 4 show the measurement results of the retardation value in the thickness direction in the colored pixel portion of the color filter formed in accordance with the manufacturing example shown above.

<Comparative example>
The color filter which does not comprise a liquid crystal phase difference layer was produced using the colorant in the said Example. The results are shown in Tables 5 and 6.

  The color filters of the examples and comparative examples obtained as described above are narrowed by a deflection film so that the deflection axes are parallel and orthogonal, and a three-wavelength tube backlight (Tc = 6,000 K) is installed on the back surface. Then, using a luminance meter (Topcon, BM-5A), chromaticity was measured from the front direction and an oblique 45 ° direction. The results are shown in FIGS.

  From the above results, no major changes were observed in the appearance and chromaticity from the front direction, but in the oblique 45 ° direction, those that exhibited reddish purple or red black in the comparative example were based on the examples. It was confirmed that a neutral gray color was obtained by the phase difference control effect.

It is a schematic sectional drawing which shows the color filter provided with the phase difference control layer which concerns on one embodiment of this invention. It is process drawing for demonstrating the manufacturing process of the color filter provided with the phase difference control layer shown in FIG. It is the figure which showed the relationship between the wavelength and the light transmittance in the semi-light-shielding area | region of the photomask A. FIG. 4 is a diagram showing the relationship between wavelength and light transmittance in a semi-shielding region of a photomask B. It is the figure which showed the relationship between the wavelength and the light transmittance in the semi-light-shielding area | region of the photomask C. It is the figure which showed the relationship between the wavelength and the light transmittance in the semi-light-shielding area | region of the photomask D. It is a figure which shows the measurement result of the color filter produced in the Example and comparative example of this invention. It is a figure which shows the measurement result of the color filter produced in the Example and comparative example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Color filter substrate 2 ... Transparent substrate 3 ... Black matrix 4 ... Colored pixel layer 5 ... Liquid crystal phase difference layer 6 ... Photomask

Claims (3)

  In a color filter substrate comprising a colored pixel layer on a transparent substrate and a retardation control layer containing a liquid crystal compound below or above the colored pixel layer, the retardation control layer comprises a total light shielding region, a total transmission region, and light. Through a photomask having a semi-light-shielding region having a transmittance of 0 to 40% at wavelengths of 300 to 340 nm, 5 to 80% at 340 to 370 nm, and 20 to 100% at 370 to 500 nm, ultraviolet rays are transmitted to the colored pixels. A color filter substrate characterized in that the ultraviolet curable liquid crystal compound applied to the lower part or the upper part is irradiated with a liquid crystal compound having a different degree of orientation for each color of the colored pixel layer.   2. The ultraviolet curable liquid crystal compound includes a liquid crystal compound exhibiting at least a thermotropic property and having a functional group capable of being polymerized and / or cross-linked, and an optical and / or thermal polymerization initiator. Color filter substrate.   A liquid crystal display device using the color filter substrate according to claim 1.

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